水平前向插入式流速仪对流速场影响的实验研究

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清华大学辅仁网/2017-07-07

王浩¹, 陈槐², 李丹勋¹, 王兴奎¹

1. 清华大学水沙科学与水利水电工程国家重点实验室, 北京 100084;
2. 南京水利科学研究院水文水资源与水利工程科学国家重点实验室, 南京 210029

Impact of horizontal plug-in flow meterson the velocity field-An experimental study

WANG Hao¹, CHEN Huai², LI Danxun¹, WANG Xingkui¹

1. State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China;
2. State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China

摘要:

输出: BibTeX | EndNote (RIS)

摘要前向插入式流速仪在工作时其探头会对待测流场造成干扰，该文对简化流速仪模型的干扰范围进行了测量和分析。简化模型仿毕托管（Pitot tube）形状，水平放置于明槽流场中，采用粒子图像测速（PIV）技术测得代表性平面瞬时二维流场。通过分析流场的沿程变化特征，确定了流速仪模型对其正前方水流的影响距离。实验结果表明：流向速度随距模型顶点距离的增大逐渐增加最后趋于来流速度，而水流的展向速度、紊动强度和雷诺应力（Reynolds stress）均随距模型顶点距离的增大而逐渐减小最后趋于稳定；流速仪对其前方水流的流速影响距离较大，对紊动强度的影响距离较小；流速仪对前方水流影响距离随模型直径增大而增大，在实验条件下，影响距离与模型直径成正比。

关键词 ：粒子图像测速(PIV),毕托管,流速,紊动强度,雷诺应力

Abstract：Horizontal plug-in flow meters disturb the velocity fields when deployed to measure rates flow. The spatial extent of such disturbances has been experimentally studied here on a simplified flow meter model. The Pitot tube used as the flow model was placed horizontally in the water flow with instantaneous two-dimensional velocity fields also measured by particle image velocimetry (PIV). Analysis of the spatial variations of the velocity fields in front of the model shows that the streamwise velocity increases with the distance from the model nose and gradually approaches that of the incoming flow with the spanwise velocity, turbulent intensities, and Reynolds stresses decreasing with the distance. The streamwise velocity requires the longest distance to recover from the disturbance with the turbulent intensity requires the shortest distance. The spatial extent of the disturbance is proportional to the flow meter diameter.

Key words：particle image velocimetry (PIV)Pitot tube velocity turbulence intensity Reynolds stress

收稿日期: 2015-01-07 出版日期: 2016-12-20

ZTFLH:

TV131.2+9

通讯作者:李丹勋,研究员,E-mail:lidx@tsinghua.edu.cnE-mail: lidx@tsinghua.edu.cn

引用本文:

王浩, 陈槐, 李丹勋, 王兴奎. 水平前向插入式流速仪对流速场影响的实验研究[J]. 清华大学学报（自然科学版）, 2016, 56(12): 1271-1277.
WANG Hao, CHEN Huai, LI Danxun, WANG Xingkui. Impact of horizontal plug-in flow meterson the velocity field-An experimental study. Journal of Tsinghua University(Science and Technology), 2016, 56(12): 1271-1277.

链接本文:

http://jst.tsinghuajournals.com/CN/10.16511/j.cnki.qhdxxb.2016.25.037或 http://jst.tsinghuajournals.com/CN/Y2016/V56/I12/1271

图表:

图1 实验装置示意图(L为与模型顶点的流向距离)

图2 Pitot管模型绕流流线俯视图

表1 实验条件

图3 Pitot管模型绕流流场等值线图

图４流向速度沿程分布规律

图５展向速度沿程分布规律

图6 流向紊流强度沿程分布规律

图7 展向紊流强度沿程分布规律

图8 Reynolds应力沿程分布规律

图9 阈值判定

表2 模型对流场影响距离

图10 模型对流场影响范围与模型直径关系图

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